PSB RFRenovation and upgrade plans

M.Paoluzzi BE/RF 25 November 2011

Summary

Existing RF systems.Foreseen consolidation / upgrade.New technology for C02 and C04.Advantages / Risks.5-cells Finemet® cavity prototype.Foreseen tests.Planning.

Existing RF systems

C02

Frequency range 0.6 (*1.0) – 1.8 MHz Gap Voltage 8 kV Installed in sections 7L1 and 10L1

C04

Frequency range 1.2 (*2.0) – 3.8 MHz Gap Voltage 8 kV Installed in section 13L1

* Frequency with injection from LINAC4

C16

Frequency range 6.0 – 16 MHz Gap Voltage 6 kV Installed in section 5L1

Three systems are presently installed in the machine:

Foreseen consolidation/upgradeIn the ring:

• Keep the cavities• Keep the C02 and C16 final amplifiers• Redesign the C04 final amplifier to:

• Increase the mean available RF power• Increase the available RF current for beam loading compensation.• Deal with the foreseen 2 GeV energy upgrade.

• Replace all the irradiated cables.

On the surface:• Replace the interlock system with modern PLC.• Replace the interfaces with the control system (G64!!!).• Move the AVC and Tuning loops to the new digital beam control electronics.• Implement new protections.• Replace the 6 kV - 8 kV Anode HV power supplies and grid bias supplies.• Install new stabilized tubes filament heaters.• Replace tuning supplies.

New technology for C02 and C04.

2-Rings cavity

Size compatible with PSB.

VGap>700 VPeak Freq > 600 KHzP = 2 x 670 WLength =13 cm

A substantial improvement could be achieved using wideband (0.6MHz to 4MHz) , Finemet® loaded cavities.

Finemet exhibits wideband response

10

100

1000

1.E+05 1.E+06 1.E+07 1.E+08

Ω

Freq [Hz]

|Z|

RP

XL

XC

CP mostly depends on geometry and drives the high frequency response. The capacitive effect is enhanced by the final stage output capacitance.

RP and LP drive the low frequency response. They and are mostly dependent on Finemet® Characteristics.

A basic cell configuration composed of one gap and two cores gives many

advantages:

Full exploitation of the Finemet®

wideband response. Power requirements in the range of

compact solid-state amplifiers. Fast RF feedback feasible to reduce

the gap impedance and compensate the beam induced voltage.

Gap voltage compatible with solid-state gap shorting devices.

B E A M

F I N E M E T

G A P

R F i n

G a p

In the available space a substantial voltage increase can be achieved or hot spares can be installed.

Advantages / RisksAdvantages

• Single system to cover C02 and C04 frequency range.• Modular system.• Solid-state amplifier.• Multi harmonic operation.• No tuning.• Substantial increase of installed RF voltage (up to 300%).• Increased system reliability (hot back-up by on line spare cells).

Risks:• New technology.• New configuration• Completely new design.• Different beam compensation scheme.• …?

Tests with beam absolutely needed.

5-cells Finemet® cavity prototype

Vacuum chamber.

5-cells open cavity. Full assembly.Solid-State amp.

Installation layout in PSB 6L1.

Finemet® on a cooling ring.

Foreseen tests

Beam test required to study:• Operation with wideband cavities.• Beam loading compensation.• Beam instabilities build-up.• Amplifier reliability.• … and much more!

• Beam will be initially accelerated with the existing system to study the beam induced voltage and compensation effectiveness (RF feedback).

• The new Finemet® system will then be used for acceleration using it ether in parallel with the existing one or alone.

• PPM operation.• Each gap equipped with shorting relays.• Dedicated beam control low level electronics available.

PlanningFinemet®

• 2011 Design, produce and install in 6L1 a test cavity (5 cells, 3 kV).

• 2012 Beam test on dedicated users and MDs.

• 2013 - 2014 13 cells, 8 kV installed in 6L1.

• 2015 Beam test on dedicated users and MDs.

C02 and C04 standard

• 2011 Design an upgraded C04 final amplifier and renovate test place.

• 2012 – 2014 C04 tests in the test place. C02 and C04 tuning and filament supplies studies.

• 2015 Specification of items for C02 and C04 consolidation.

• 2016 - ? Production of cells to fully equip the PSB with wideband cavities instead of C02 and C04!

Procurement of power supplies, ITL, new cables installation, etc.

• 2016 - ? Production of C04 upgraded amplifiers.

Procurement of power supplies, ITL, new cables installation, etc. for C02 and C04 consolidation

Depending on test results

Parallel activities

• LS 2 Wideband cavities installation or C02 and C04 consolidation + C16 consolidation

C16

• 2012 - 2014 C16 Tuning and

filament supplies studies.

• 2015 Specification of items for consolidation.

`

• 2016 - ? Procurement of power supplies, ITL, new cables installation, etc. for C16 consolidation

Parallel activities

THANK YOU FOR YOUR ATTENTION!